Loh is currently associate conductor of the Dallas Symphony; he previously served in the same position at the Colorado Symphony.
He succeeds Clyde Mitchell, whose three-year term ended last year.
The NPP was created in 1972 by the merger of the Wilkes-Barre Philharmonic and the Scranton Philharmonic. Past music directors include Hugh Woolf, later music director of the New Jersey Symphony.
Also this week, the Pittsburgh Symphony named Loh as its new assistant conductor, the Pittsburgh Tribune-Review reports. According to the paper, the PSO conducted a fruitless search for a new assistant conductor earlier this year. After a staff member heard Loh conduct the NPP earlier this month, the orchestra offered the position to him.